Vacuum deposition of selenium alloy

Abstract

A process for fabricating an electrophotographic imaging member is disclosed comprising providing in a vacuum chamber at least one crucible containing particles of an alloy comprising selenium and an alloying component selected from the group consisting of tellurium, arsenic, and mixtures thereof, providing a substrate in the vacuum chamber, applying a partial vacuum to the vacuum chamber, and rapidly heating the crucible to a temperature between about 250° C. and 450° C. to deposit a thin continuous selenium alloy layer on the substrate. A plurality of selenium containing layers may be formed by providing in a vacuum chamber at least one first layer crucible containing particles of selenium or a sellenium alloy, at least one second layer crucible containing particles of an alloy comprising selenium, and a substrate, applying a partial vacuum to the vacuum chamber, heating the particles in the first layer crucible to deposit a thin continuous selenium or a selenium alloy first layer on the substrate, maintaining the particles in the second layer crucible at a first temperature below about 130° C. while the thin continuous selenium or a selenium alloy first layer is being deposited on the substrate, and rapidly heating the particles in the second layer crucible to a second temperature between about 250° C. and about 450° C. to deposit a thin continuous selenium alloy second layer on the substrate.

What is claimed is: 
     
       1. A process for fabricating an electrophotographic imaging member comprising providing in a vacuum chamber at least one first layer crucible containing particles of selenium or a selenium alloy, at least one second layer crucible containing particles of an alloy comprising selenium and an alloying component selected from the group consisting of tellurium, arsenic, and mixtures thereof, and a substrate, applying a partial vacuum to said vacuum chamber, heating said particles in said first layer crucible to deposit a thin continuous selenium or a selenium alloy first layer on said substrate, maintaining said particles in said second layer crucible at a first temperature below about 130° C. while said thin continuous selenium or a selenium alloy first layer is being deposited on said substrate, and rapidly heating the particles in said second layer crucible to a second temperature between about 250° C. and about 450° C. to deposit a thin continuous selenium alloy second layer on said substrate. 
     
     
       2. A process for fabricating an electrophotographic imaging member in accordance with claim 1 wherein said first layer is a charge transport layer of a selenium arsenic alloy. 
     
     
       3. A process for fabricating an electrophotographic imaging member in accordance with claim 1 wherein said second layer is a charge generator layer. 
     
     
       4. A process for fabricating an electrophotographic imaging member in accordance with claim 1 including rapidly raising the temperature of said second layer crucible to between about 300° C. and about 375° C. in between about 5 minutes and about 18 minutes at the completion of evaporation of said particles of selenium or a selenium alloy from said first layer crucible. 
     
     
       5. A process for preparing an electrophotographic imaging member in accordance with claim 4 wherein said alloy comprises a halogen dopant. 
     
     
       6. A process for preparing an electrophotographic imaging member in accordance with claim 4 wherein said alloy comprises an alloy of selenium and arsenic. 
     
     
       7. A process for preparing an electrophotographic imaging member in accordance with claim 4 wherein said alloy comprises an alloy of selenium and tellurium. 
     
     
       8. A process for preparing an electrophotographic imaging member in accordance with claim 4 wherein said alloy comprises an alloy of selenium, arsenic and tellurium. 
     
     
       9. A process for preparing an electrophotographic imaging member in accordance with claim 4 wherein said heating of said particles to a temperature between about 85° C. and and about 130° C. is maintained until 100 percent of said amorphous core of selenium alloy in said particles is crystallized. 
     
     
       10. A process for preparing an electrophotographic imaging member in accordance with claim 4 comprising, prior to rapid heating said particles in a vacuum coater, preparing a mixture of said particles in which 100 percent of said amorphous core is crystallized and additional particles of an amorphous alloy comprising selenium and a dopant selected from the group consisting of tellurium, arsenic, and mixtures thereof, said additional particles having an average particle size of at least about 300 micrometers and an average weight of less than about 1000 mg, said additional particles comprising up to about 75 percent by weight of the total weight of said mixture. 
     
     
       11. A process for preparing an electrophotographic imaging member in accordance with claim 1 wherein said particles of an alloy comprising selenium and an alloying component selected from the group consisting of tellurium, arsenic, and mixtures thereof are beads. 
     
     
       12. A process for preparing an electrophotograhic imaging member in accordance with claim 1 wherein said particles of an alloy comprising selenium and an alloying component selected from the group consisting of tellurium, arsenic, and mixtures thereof are pellets.